2002 35th o2 sensors

[last ss]

im having trouble with the o2 sensors setting numerous codes,0155,1133 just the latest.the car has slp headers and exhaust with random cats.it dosn't set ses lite.chevy repalced 2 sensors about 2 years ago.the car has 8k miles and i was told the o2 sensors are probably dirty from sitting so long.when scanned they seem to be working fine.should i replace them due to thier lack of use and setting codes?is this covered under the emmissions warranty?

[ConElite]

I doubt it will be covered by warranty. If its setting codes there is something wrong. I dont think O2 sensors go out b/c lack of use. Thats to little miles for them to be acting up

[Jeff_in_Atl]

im having trouble with the o2 sensors setting numerous codes,0155,1133 just the latest.the car has slp headers and exhaust with random cats.it dosn't set ses lite.chevy repalced 2 sensors about 2 years ago.the car has 8k miles and i was told the o2 sensors are probably dirty from sitting so long.when scanned they seem to be working fine.should i replace them due to thier lack of use and setting codes?is this covered under the emmissions warranty?

I don't know about the 0155 but I do know what the 1133 is. This is actually caused by the SLP headers. I have the same problem with my 02 Vette with SLP headers. It's not the brand or anything. What causes this is the headers (any long tube headers on an OBDII car) moves the collectors further away from the engine. This causes a time delay in the engine calibration from the computer to the pickup of the oxygen sensor.

The 1133 code isn't a current code. It is a history code. That isn't a good way to say it but what I am trying to say is it is a bleep. It isn't a continuous code like some are. It's just showing you that it sensed a problem for a brief moment. I can clear mine and it might not come back for a month. Sometimes it might come back in 10 minutes. I can clear mine from the dash without a scanner though.

There are 2 fixes.
1. Get someone to take out the software that sets off the 1133 code. This will stop the code but it dumbs down the computer. The computer won't be able to compensate for conditions as well. I can tell you from experience that this will result in a loss of gas mileage of 1-2 mpg too. I had this done to my car and I had them put it back because of the loss of mileage.

2. Replace the rear O2s with 2 more factory front O2s. Another words you will have 2 front O2s in the front holes and 2 front O2s in the rear holes. The front O2s are "stronger" O2s. That is why they cost twice what the rear O2s cost. However front O2s have a different plug than the rear ones have. You will have to get 2 adapter harnesses. I have looked all over the place and the only place I know of that you can get them is MTI Motorsports in Marietta Ga. This is supposed to fix the insufficient switches problem. I have 2 front O2s and 2 adapters in the back of my car right now. I have not put them in to tell you for sure in my experience because mine doesn't do it that often. If it doesn't get any worse I will leave it until it gets 100,000 miles on it when they should get replaced anyway. If yours isn't doing that often and you have a scanner that you can clear the codes and it doesn't bother you it won't hurt to drive it this way. If you have to get emissions this can be a problem.

Oh federal law requires manufacturers to cover all cars for emissions up to 80,000 miles regardless of warrantee or age of car. Rear O2s are emissions related and should be covered. However if your car is throwing the 1133 it will come back some day. Maybe if you got the wiring adapters you could get them to put front O2s in it instead of rear ones.